UPDATE OF MINERAL LAND CLASSIFICATION: AGGREGATE …

1 california department OF conservation DIVISION OF MINES AND GEOLOGY DMG OPEN-FILE REPORT 96-04 UPDATE OF MINERAL land classification : AGGREGATE MATERIALS IN THE WESTERN SAN DIEGO COUNTY PRODUCTION-CONSUMPTION REGION THE RESOURCES AGENCY DOUGLAS P. WHEELER SECRETARY FOR RESOURCES 1996 Division of Mines and Geology STATE OF california PETE WILSON GOVERNOR department OF conservation ELiN D. MILLER DIRECTOR DIVISION OF MINES AND GEOLOGY JAMES F. DAVIS, STATE GEOLOGIST Copyright 1996 by the california department of conservation , Division of Mines and Geology. All rights reserved. No part of this publication may be reproduced without written consent of the Division of Mines and Geology. UPDATE OF MINERAL land classification : AGGREGATE MATERIALS IN THE WESTERN SAN DIEGO COUNTY PRODUCTION-CONSUMPTION REGION BY Russell V.

2 Miller DMG OPEN-FILE REPORT 96-04 1996 california department OF conservation DIVISION OF MINES AND GEOLOGY 801 K STREET SACRAMENTO, CA 95814-3531 TABLE OF CONTENTS EXECUTIVE SUMMARY .. vii PART I - classification OF IN WESTERN PART PART PART PART SAN DIEGO COUNTY INTRODUCTION '. REEVALUATION OF PCC-GRADE AGGREGATE IN WESTERN SAN DIEGO COUNTY I. , Concepts Used in Identifying Available AGGREGATE Resources ~ Calculation of Available Resources Reserves and Resources Factors Considered in Calculations Resource Sectors Newly Identified AGGREGATE Resource Areas Classified MRZ-2 Sycamore Ridge Property Pankey Ranch site San Marcos Quarry TTT Quarry.

3 San Vincente Creek Hester's Granite Quarry Jamul Quarry PCC-Grade AGGREGATE Deposits Below Minimum Threshold Value Harmony Grove Quarries vista Quarry AGGREGATE Resources in Western San Diego County Recycled AGGREGATE II -ESTIMATED 50-YEAR CONSUMPTION OF AGGREGATE IN WESTERN SAN DIEGO COUNTY AGGREGATE PRODUCTION IN WESTERN SAN DIEGO COUNTY CORRELATIONS BETWEEN AGGREGATE PRODUCTION AND POPULATION PROJECTED AGGREGATE DEMAND THROUGH THE YEAR 2045 COMPARISON OF THE 50-YEAR AGGREGATE DEMAND WITH CURRENT RESERVES III -ALTERNATIVE SOURCES OF AGGREGATE CRUSHED ROCK SOURCES.

4 ALLUVIAL DEPOSITS TEMESCALVALLEY PRODUCTION AREA IN RIVERSIDE COUNTY IV -REVIEW OF THE WESTERN SAN DIEGO COUNTY PRODUCTION-CONSUMPTION REGION V -CONCLUSIONS .,. ACKNOWLEDGMENTS .. REFERENCES .. APPENDIX .. iii 1 1 7 7 8 8 8 9 11 11 11 11 12 12 12 12 13 13 13 13 15 16 16 21 22 26 27 27 28 28 29 32 34 35 37 FIGURES Page Fiqure 1. Location of the western San Diego county production-consumption Region 2 Fiqure 2. Index map to Plates 2 through 14 .. Fiqure 3. Index map of Geological Survey quadrangles covering the Western San Diego County Production- 3 consumption Region 4 Fiqure 4. Map of western San Diego County area showing locations of sand and gravel mines that have permits to mine AGGREGATE .

5 17 Figure 5. AGGREGATE production in western San Diego County--1960 to 1994, with projection to 2045 25 Figure 6. comparison of AGGREGATE production in the Western San Diego County production-consumption Region for the years 1980 to 1994, with the forecast in special Report 153 (Kohler and Miller, 1982) 30 Figure 7. comparison of population in the Western San Diego County production-consumption Region for the years 1980 to 1994, with the forecast in special Report 153 (Kohler and Miller, 1982) 31 Fiqure 8. california MINERAL land classification Diagram: Diagrammatic relationship of MINERAL resource zone categories to the resource/reserve classification system. Adapted from Bureau of Geological Survey (1980) 38 iv Table 1.

6 TABLES Lead agencies (county and incorporated city governments) in western San Diego county Table 2. Unpermitted pcc-grade AGGREGATE resources unavailable due to urbanization in designated Page .. 5 areas in western San Diego county . 14 Table 3. Population, AGGREGATE production, and per capita consumption in western San Diego county during the years 1980 through 1994 23 Table 4. projected AGGREGATE consumption through the year 2045 in western San Diego county 24 Table 5. Summary of AGGREGATE resources and projected 50-year consumption for western San Diego County. 26 v PLATES Plate 1. Generalized MINERAL land classification Map of western San Diego county-- AGGREGATE Resources Only. Plate 2.

7 Plate 3. Plate 4. Plate 5. Plate 6. Plate . 7. Plate 8. Revised MINERAL land classification Maps Bonsall Quadrangle San Marcos Quadrangle Rancho Santa Fe Quadrangle San Vicente Reservoir Quadrangle El cajon Quadrangle Jamul Mountains Quadrangle Dulzura Quadrangle Maps showing Urbanization of Designated Areas since 1985 Plate 9. Plate 10. Plate 11. Plate 12. Plate 13. Plate 14. San Luis Rey River Resource Area San Pasqual Valley Resource Area Kearney Mesa-Mission Valley Resource Area upper San Diego River Resource Area Sweetwater River Resource Area Otay Valley, Tijuana River, and Border Highlands Resource Areas vi EXECUTIVE SUMMARy This report updates information presented in a classification study on portland cement concrete (PCC)-grade AGGREGATE in western San Diego County in 1982.

8 That study was published by the department of conservation 's Division of Mines and Geology (DMG) as Special Report 153 - MINERAL land classification : AGGREGATE Materials in the Western San Diego County Production-Consumption Region (Kohler and Miller, 1982). Special Report 153 included the urban and urbanizing parts of western San Diego County as a single production-consumption (P-C) region. Active mines within the county that extract MINERAL commodities other than PCC-grade AGGREGATE , were not classified in this study.. The material specifications for PCC-grade AGGREGATE are more restrictive than the specifications for AGGREGATE used in other applications. Deposits that are acceptable for use as PCC-grade AGGREGATE are the rarest and most valuable of AGGREGATE resources.

9 Data contained within this UPDATE were current as of January 1996, with the exception of the figures relating to annual AGGREGATE production, which are complete only to December 1994. In this case, the 1994 data is the most recent available. The initial classification report--Special Report 153--and the subsequent designation of the area by the state Mining and Geology Board in 1985, both required local lead agencies in western San Diego County to incorporate that data into their General Plan and adopt MINERAL Resource Management Policies to address that data. The specific actions required of local lead agencies by this report are that the City of San Marcos must incorporate the reclassification information on Plates 3 and 4 (Revised MINERAL land classification Maps of the San Marcos and Rancho Santa Fe Quadrangles) into their general plan and the County of San Diego must incorporate the reclassification information on Plates 5 and 6 (Revised MINERAL land classification Maps of the San Vicente Reservoir and EI Cajon Quadrangles) and the classification ~nformation on Plates 7 and 8 (Revised MINERAL land classification Maps of the Jamul Mountains and Dulzura Quadrangles) into their general plan.

10 Based on this UPDATE study and assuming that the consumption forecast is accurate, the following conclusions were reached: o The AGGREGATE reserves have significantly decreased since the 1982 study. The 352 million tons of presently permitted PCC-grade AGGREGATE reserves within western San vii Diego county are enough to continue to supply the demand of the county for 20 years -until the year 2016. In 1982, the region had 78 million tons more--430 million tons--for a 32-year supply. More than 80 percent of the total drop in AGGREGATE reserves from 1980 to 1995 is accounted for by the drop in access to instream sand reserves. This will eventually lead to higher costs for PCC-grade sand. o As of January 1996, 27 mines, 24 of which are active, operated by 16 different mining companies were producing, or permitted to produce, PCC-grade AGGREGATE in western San Diego county.